There were many striking things about the night Obama was elected. But one of the most striking was how real, how unlike a movie, the events of that historic night were. We've become used to the big dramas of US life being foreshadowed by fiction. As they watched the events of 9/11 blaze across their TV screens, many people reported guiltily that - despite being aware of the full horror of what they were witnessing - they found it hard to believe they weren't watching a movie. For decades, Hollywood had entertained us with the idea of terror raining down on New York; it was hard to believe this wasn't a Saturday night at the flicks.

Before 9/11, the thrill of such movies for the US audience was that, although an attack could feasibly happen, few believed it ever would. Letting King Kong or armies of aliens loose on New York was simply a way of testing how safe Americans actually felt - which seemed to be very safe indeed. Shaking off the sensation that this was, somehow, one big movie was part of the trauma of 9/11 for America.

Obama, however, seemed to be at the centre of a very real event. But then fiction has long been preparing us for a Democrat victory. The West Wing provided a parallel Democratic White House, existing in a happy liberal universe where Clinton had never lost the trust of the American people and his gleaming legacy could be unquestioningly pursued. And fiction has also been preparing us for a black president. Look guys, the movie-makers have been saying, we know Bush looks awkward, so here's someone who does it better. We've had Morgan Freeman in the disaster movie Deep Impact, Dennis Haysbert in the highly cinematic 24, even Chris Rock in the comedy Head of State. We've grown used to seeing the camera zooming into the Oval Office to show a deeply authoritative black man - so much wiser, so much nobler than the real-life president, with his fumbled syntax and cowboy heels - preparing to address the nation about that old headache, an imminent invasion from Mars.

The film-makers could be sure of a Democratic victory in the not-too-distant future, but few can have expected to see a black president by the end of the decade. How could they? Obama's victory was a sudden leap forward. Those black presidents on film and TV were a Hollywood dream, not a promise of change. We're used to reading US cinema as a picture of an idealised world. In the movies, it seemed, everyone was blonde and beautiful and the president was black. Meanwhile, in real life, we were an odd-looking crowd and the president was a white man, and seemed likely to remain so. That was the unconscious message.

What no film-maker seemed to predict was Obama's skinny, boyish energy. Writers and directors clearly felt it was progressive to cast Freeman, Rock et al as president. But there was something ultimately reactionary in this, a desire to return to the idea of a president as a wise, kind father of the nation: the skin colour was changed only so that the image of the patriarch could be reasserted. In the real world, Clinton had strayed and seemed to be sharing power with his wife; Dubya kept on messing up and looking to please his dad. It was becoming difficult to credit a white man in the White House with the dignity and wisdom to be an all-knowing father figure, an independent alpha male. Better call for the black guy - he might save the patriarchy.

And there's the rub: "father figure" isn't Obama's shtick at all. His hair may have got a little greyer during the long campaign, but he's not playing the role of wise old dad. If anything, he's more like the bright kid who goes off to university and comes home to find his parents have become too frail to keep the house in order. "Don't worry," he says, "I'm here now. I'm bright and I'm energetic and I can help you sort out the mess." This isn't the black president of the movies; this is a character no one foresaw and scripted in advance. In 1980, Ronald Reagan stepped from the cinema screen into the presidency and established the free market dogma that has held sway for more than 25 years. That dogma is finally collapsing, in a disaster that's scarier than anything in Deep Impact. And now Obama's proving how wrong the movie-makers were. He's a black president, but unlike any they imagined. This time it's real.